I started shooting in the late 70's and flash bulbs were already out of production. The Vivitar 283 had been out for most of that decade, and was the go-to flash.
But we shot a lot of flash bulbs because 1) the unit were cheap (lots of discarded units) and 2) NOS bulbs were plentiful, we would pick up boxes of them at swap-meets for nothing.
Flash bulbs came in multiple flavours, FP, M and X sync optimized, and daylight/non-daylight balanced.
FP bulbs had a long uniform output so you could sync a focal plan shutter at higher speeds (as HSFS today)
M bulbs took a little time to build up to full brightness, but did not have a uniform output, and were used with leaf shutters at higher speeds.
X bulbs were fast bulbs that worked on X sync - and because of these bulbs, all MF cameras back then could use flash bulbs, including latter ones that did not have an FP or M sync.
We bought every FP bulb we could find, because HSFS was not available back then. But M/X bulbs were still useful, as they were way brighter than the 283.
Fun times.